diff --git a/src/renderer/components/sidebar/SidebarTaskItem.tsx b/src/renderer/components/sidebar/SidebarTaskItem.tsx
index 2b5c1a12..fdbe3be9 100644
--- a/src/renderer/components/sidebar/SidebarTaskItem.tsx
+++ b/src/renderer/components/sidebar/SidebarTaskItem.tsx
@@ -1,7 +1,6 @@
 import { memo, useEffect, useMemo, useRef, useState } from 'react';
 
 import { useAppTranslation } from '@features/localization/renderer';
-import { Tooltip, TooltipContent, TooltipTrigger } from '@renderer/components/ui/tooltip';
 import { getTeamColorSet } from '@renderer/constants/teamColors';
 import { useTheme } from '@renderer/hooks/useTheme';
 import { useUnreadCommentCount } from '@renderer/hooks/useUnreadCommentCount';
@@ -178,7 +177,7 @@ export const SidebarTaskItem = memo(function SidebarTaskItem({
   return (
     <button
       type="button"
-      className={`flex w-full cursor-pointer flex-col justify-center border-b px-2 py-1.5 text-left transition-colors hover:bg-surface-raised ${unreadBackgroundClass} ${task.teamDeleted ? 'opacity-50' : ''}`}
+      className={`sidebar-task-item flex w-full cursor-pointer flex-col justify-center border-b px-2 py-1.5 text-left transition-colors hover:bg-surface-raised ${unreadBackgroundClass} ${task.teamDeleted ? 'opacity-50' : ''}`}
       style={{ borderColor: 'var(--color-border)' }}
       onClick={() => {
         if (!isRenaming) {
@@ -225,37 +224,29 @@ export const SidebarTaskItem = memo(function SidebarTaskItem({
             />
           </div>
         ) : (
-          <Tooltip>
-            <TooltipTrigger asChild>
+          <span
+            className="line-clamp-2 text-[13px] font-medium leading-tight"
+            style={{ color: 'var(--color-text-muted)' }}
+            title={displaySubject}
+          >
+            <StatusIcon className={cn('mr-1.5 inline-block align-[-1px]', statusIconClassName)} />
+            {unreadCount > 0 &&
+              (unreadCount === 1 ? (
+                <span className="mr-1 inline-block size-1.5 rounded-full bg-blue-400 align-middle" />
+              ) : (
+                <span className="mr-1 inline-flex size-3.5 items-center justify-center rounded-full bg-blue-500 align-middle text-[8px] font-bold leading-none text-white">
+                  {unreadCount > 9 ? '9+' : unreadCount}
+                </span>
+              ))}
+            {displaySubject}
+            {isTeamTaskNeedsFixActionable(task) && (
               <span
-                className="line-clamp-2 text-[13px] font-medium leading-tight"
-                style={{ color: 'var(--color-text-muted)' }}
+                className={`ml-1.5 inline-block rounded-full px-1.5 py-0.5 align-middle text-[10px] font-medium leading-none ${REVIEW_STATE_DISPLAY.needsFix.bg} ${REVIEW_STATE_DISPLAY.needsFix.text}`}
               >
-                <StatusIcon
-                  className={cn('mr-1.5 inline-block align-[-1px]', statusIconClassName)}
-                />
-                {unreadCount > 0 &&
-                  (unreadCount === 1 ? (
-                    <span className="mr-1 inline-block size-1.5 rounded-full bg-blue-400 align-middle" />
-                  ) : (
-                    <span className="mr-1 inline-flex size-3.5 items-center justify-center rounded-full bg-blue-500 align-middle text-[8px] font-bold leading-none text-white">
-                      {unreadCount > 9 ? '9+' : unreadCount}
-                    </span>
-                  ))}
-                {displaySubject}
-                {isTeamTaskNeedsFixActionable(task) && (
-                  <span
-                    className={`ml-1.5 inline-block rounded-full px-1.5 py-0.5 align-middle text-[10px] font-medium leading-none ${REVIEW_STATE_DISPLAY.needsFix.bg} ${REVIEW_STATE_DISPLAY.needsFix.text}`}
-                  >
-                    {tCommon('tasks.reviewState.needsFix')}
-                  </span>
-                )}
+                {tCommon('tasks.reviewState.needsFix')}
               </span>
-            </TooltipTrigger>
-            <TooltipContent side="right" sideOffset={6}>
-              {displaySubject}
-            </TooltipContent>
-          </Tooltip>
+            )}
+          </span>
         )}
       </div>
 
diff --git a/src/renderer/components/team/TeamListView.tsx b/src/renderer/components/team/TeamListView.tsx
index 27c33657..5a6b9845 100644
--- a/src/renderer/components/team/TeamListView.tsx
+++ b/src/renderer/components/team/TeamListView.tsx
@@ -356,6 +356,12 @@ const ActiveTeamCard = ({
   const launchMode: TeamLaunchDialogMode = status === 'offline' ? 'launch' : 'relaunch';
   const launchLabel =
     launchMode === 'relaunch' ? t('list.actions.relaunchTeam') : t('list.actions.launchTeam');
+  const launchTitle =
+    launchingTeamName === team.teamName ? t('list.actions.launching') : launchLabel;
+  const stopTitle =
+    stoppingTeamName === team.teamName ? t('list.actions.stopping') : t('list.actions.stopTeam');
+  const copyTitle = t('list.actions.copyTeam');
+  const deleteTitle = t('list.actions.deleteTeam');
 
   return (
     <div
@@ -400,78 +406,51 @@ const ActiveTeamCard = ({
             </div>
             <div className="flex shrink-0 gap-1">
               {canLaunch ? (
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <button
-                      type="button"
-                      className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-emerald-500/10 hover:text-emerald-300 disabled:opacity-50 group-hover:opacity-100"
-                      onClick={(event) =>
-                        onLaunchTeam(
-                          team.teamName,
-                          team.projectPath ?? undefined,
-                          launchMode,
-                          event
-                        )
-                      }
-                      disabled={launchingTeamName === team.teamName}
-                      aria-label={launchLabel}
-                    >
-                      <Play size={14} fill="currentColor" />
-                    </button>
-                  </TooltipTrigger>
-                  <TooltipContent side="bottom">
-                    {launchingTeamName === team.teamName
-                      ? t('list.actions.launching')
-                      : launchLabel}
-                  </TooltipContent>
-                </Tooltip>
+                <button
+                  type="button"
+                  className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-emerald-500/10 hover:text-emerald-300 disabled:opacity-50 group-hover:opacity-100"
+                  onClick={(event) =>
+                    onLaunchTeam(team.teamName, team.projectPath ?? undefined, launchMode, event)
+                  }
+                  disabled={launchingTeamName === team.teamName}
+                  aria-label={launchTitle}
+                  title={launchTitle}
+                >
+                  <Play size={14} fill="currentColor" />
+                </button>
               ) : null}
               {status === 'active' || status === 'idle' ? (
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <button
-                      type="button"
-                      className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-amber-500/10 hover:text-amber-300 disabled:opacity-50 group-hover:opacity-100"
-                      onClick={(event) => onStopTeam(team.teamName, event)}
-                      disabled={stoppingTeamName === team.teamName}
-                      aria-label={t('list.actions.stopTeam')}
-                    >
-                      <Square size={14} fill="currentColor" />
-                    </button>
-                  </TooltipTrigger>
-                  <TooltipContent side="bottom">
-                    {stoppingTeamName === team.teamName
-                      ? t('list.actions.stopping')
-                      : t('list.actions.stopTeam')}
-                  </TooltipContent>
-                </Tooltip>
+                <button
+                  type="button"
+                  className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-amber-500/10 hover:text-amber-300 disabled:opacity-50 group-hover:opacity-100"
+                  onClick={(event) => onStopTeam(team.teamName, event)}
+                  disabled={stoppingTeamName === team.teamName}
+                  aria-label={stopTitle}
+                  title={stopTitle}
+                >
+                  <Square size={14} fill="currentColor" />
+                </button>
               ) : null}
               {!team.pendingCreate ? (
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <button
-                      type="button"
-                      className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-blue-500/10 hover:text-blue-300 group-hover:opacity-100"
-                      onClick={(event) => onCopyTeam(team.teamName, event)}
-                    >
-                      <Copy size={14} />
-                    </button>
-                  </TooltipTrigger>
-                  <TooltipContent side="bottom">{t('list.actions.copyTeam')}</TooltipContent>
-                </Tooltip>
+                <button
+                  type="button"
+                  className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-blue-500/10 hover:text-blue-300 group-hover:opacity-100"
+                  onClick={(event) => onCopyTeam(team.teamName, event)}
+                  aria-label={copyTitle}
+                  title={copyTitle}
+                >
+                  <Copy size={14} />
+                </button>
               ) : null}
-              <Tooltip>
-                <TooltipTrigger asChild>
-                  <button
-                    type="button"
-                    className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-red-500/10 hover:text-red-300 group-hover:opacity-100"
-                    onClick={(event) => onDeleteTeam(team.teamName, !!team.pendingCreate, event)}
-                  >
-                    <Trash2 size={14} />
-                  </button>
-                </TooltipTrigger>
-                <TooltipContent side="bottom">{t('list.actions.deleteTeam')}</TooltipContent>
-              </Tooltip>
+              <button
+                type="button"
+                className="shrink-0 rounded p-1 text-[var(--color-text-muted)] opacity-0 transition-opacity hover:bg-red-500/10 hover:text-red-300 group-hover:opacity-100"
+                onClick={(event) => onDeleteTeam(team.teamName, !!team.pendingCreate, event)}
+                aria-label={deleteTitle}
+                title={deleteTitle}
+              >
+                <Trash2 size={14} />
+              </button>
             </div>
           </div>
         </div>
diff --git a/src/renderer/components/team/activity/ActivityItem.tsx b/src/renderer/components/team/activity/ActivityItem.tsx
index fac70448..2ac18f5b 100644
--- a/src/renderer/components/team/activity/ActivityItem.tsx
+++ b/src/renderer/components/team/activity/ActivityItem.tsx
@@ -10,12 +10,7 @@ import { AttachmentDisplay } from '@renderer/components/team/attachments/Attachm
 import { MemberBadge } from '@renderer/components/team/MemberBadge';
 import { TaskTooltip } from '@renderer/components/team/TaskTooltip';
 import { ExpandableContent } from '@renderer/components/ui/ExpandableContent';
-import {
-  Tooltip,
-  TooltipContent,
-  TooltipProvider,
-  TooltipTrigger,
-} from '@renderer/components/ui/tooltip';
+import { Tooltip, TooltipContent, TooltipTrigger } from '@renderer/components/ui/tooltip';
 import {
   CARD_BG,
   CARD_BG_ZEBRA,
@@ -1310,7 +1305,7 @@ export const ActivityItem = memo(
 
     return (
       <article
-        className="group overflow-hidden rounded-md"
+        className="activity-timeline-card group overflow-hidden rounded-md"
         style={{
           marginLeft: isSlashCommandResult ? 26 : isUserSent ? 15 : undefined,
           backgroundColor:
@@ -1424,27 +1419,14 @@ export const ActivityItem = memo(
                   )}
                 </div>
               </div>
-              <TooltipProvider delayDuration={1000}>
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <div>
-                      <CompactMarkdownPreview
-                        content={compactPreviewMarkdown}
-                        className="mt-1 line-clamp-2 w-full min-w-0 max-w-full break-words text-[11px] leading-4"
-                        teamColorByName={teamColorByName}
-                        onTeamClick={onTeamClick}
-                      />
-                    </div>
-                  </TooltipTrigger>
-                  <TooltipContent
-                    side="bottom"
-                    align="start"
-                    className="max-w-sm whitespace-normal break-words"
-                  >
-                    {compactPreviewTooltipText}
-                  </TooltipContent>
-                </Tooltip>
-              </TooltipProvider>
+              <div title={compactPreviewTooltipText}>
+                <CompactMarkdownPreview
+                  content={compactPreviewMarkdown}
+                  className="mt-1 line-clamp-2 w-full min-w-0 max-w-full break-words text-[11px] leading-4"
+                  teamColorByName={teamColorByName}
+                  onTeamClick={onTeamClick}
+                />
+              </div>
             </div>
           ) : !isExpanded ? (
             <div className="min-w-0 flex-1">
@@ -1506,27 +1488,14 @@ export const ActivityItem = memo(
                   )}
                 </div>
               </div>
-              <TooltipProvider delayDuration={1000}>
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <div>
-                      <CompactMarkdownPreview
-                        content={compactPreviewMarkdown}
-                        className="mt-1 line-clamp-2 w-full min-w-0 max-w-full break-words text-[11px] leading-4"
-                        teamColorByName={teamColorByName}
-                        onTeamClick={onTeamClick}
-                      />
-                    </div>
-                  </TooltipTrigger>
-                  <TooltipContent
-                    side="bottom"
-                    align="start"
-                    className="max-w-sm whitespace-normal break-words"
-                  >
-                    {compactPreviewTooltipText}
-                  </TooltipContent>
-                </Tooltip>
-              </TooltipProvider>
+              <div title={compactPreviewTooltipText}>
+                <CompactMarkdownPreview
+                  content={compactPreviewMarkdown}
+                  className="mt-1 line-clamp-2 w-full min-w-0 max-w-full break-words text-[11px] leading-4"
+                  teamColorByName={teamColorByName}
+                  onTeamClick={onTeamClick}
+                />
+              </div>
             </div>
           ) : (
             <>
diff --git a/src/renderer/components/team/activity/ActivityTimeline.tsx b/src/renderer/components/team/activity/ActivityTimeline.tsx
index da99c9f3..1c2da89b 100644
--- a/src/renderer/components/team/activity/ActivityTimeline.tsx
+++ b/src/renderer/components/team/activity/ActivityTimeline.tsx
@@ -83,6 +83,8 @@ export interface TimelineViewport {
   scrollMargin?: number;
   /** Enable virtualization (wired in a follow-up; ignored for now). */
   virtualizationEnabled?: boolean;
+  /** Optional row-count gate for compact hosts that need virtualization earlier. */
+  virtualizationRowThreshold?: number;
 }
 
 interface ActivityTimelineProps {
@@ -692,7 +694,7 @@ export const ActivityTimeline = React.memo(function ActivityTimeline({
   const shouldVirtualize =
     viewport?.virtualizationEnabled === true &&
     viewport.scrollElementRef != null &&
-    renderRows.length >= VIRTUALIZATION_ROW_THRESHOLD;
+    renderRows.length >= (viewport.virtualizationRowThreshold ?? VIRTUALIZATION_ROW_THRESHOLD);
 
   // DOM-measured distance from the scroll container's scroll origin to the
   // timeline root. We avoid re-measuring on every scroll: the offset only
diff --git a/src/renderer/components/team/activity/AnimatedHeightReveal.tsx b/src/renderer/components/team/activity/AnimatedHeightReveal.tsx
index 8ba8ed41..bdf1ef8c 100644
--- a/src/renderer/components/team/activity/AnimatedHeightReveal.tsx
+++ b/src/renderer/components/team/activity/AnimatedHeightReveal.tsx
@@ -28,6 +28,29 @@ export const AnimatedHeightReveal = ({
   style,
   containerRef,
   children,
+}: AnimatedHeightRevealProps): JSX.Element => {
+  if (!animate && !className && !style && !containerRef) {
+    return <>{children}</>;
+  }
+
+  return (
+    <AnimatedHeightRevealInner
+      animate={animate}
+      className={className}
+      style={style}
+      containerRef={containerRef}
+    >
+      {children}
+    </AnimatedHeightRevealInner>
+  );
+};
+
+const AnimatedHeightRevealInner = ({
+  animate,
+  className,
+  style,
+  containerRef,
+  children,
 }: AnimatedHeightRevealProps): JSX.Element => {
   const [shouldAnimateOnMount] = useState(() => Boolean(animate));
   const wrapperRef = useRef<HTMLDivElement | null>(null);
diff --git a/src/renderer/components/team/messages/MessagesPanel.tsx b/src/renderer/components/team/messages/MessagesPanel.tsx
index 6ec504cb..646305e8 100644
--- a/src/renderer/components/team/messages/MessagesPanel.tsx
+++ b/src/renderer/components/team/messages/MessagesPanel.tsx
@@ -363,8 +363,9 @@ export const MessagesPanel = memo(function MessagesPanel({
       // path for short lists and only switches to the windowed path once
       // the row count crosses its internal threshold.
       virtualizationEnabled: true,
+      virtualizationRowThreshold: position === 'sidebar' ? 24 : undefined,
     };
-  }, [activeScrollContainerRef]);
+  }, [activeScrollContainerRef, position]);
   const handleExpandContent = useCallback(() => {
     // no-op: user is reading expanded content, not composing
   }, []);
diff --git a/src/renderer/index.css b/src/renderer/index.css
index 0fab931e..39b03ddb 100644
--- a/src/renderer/index.css
+++ b/src/renderer/index.css
@@ -1470,6 +1470,25 @@ a[href],
   --row-zebra-bg: color-mix(in srgb, var(--color-surface-raised) 99%, var(--color-text) 1%);
   --row-zebra-hover-bg: color-mix(in srgb, var(--row-zebra-bg) 97%, var(--color-text) 3%);
   background-color: var(--row-card-bg);
+  content-visibility: auto;
+}
+
+.team-row-zebra-card {
+  contain-intrinsic-size: auto 260px;
+}
+
+.project-row-zebra-card {
+  contain-intrinsic-size: auto 190px;
+}
+
+.activity-timeline-card {
+  content-visibility: auto;
+  contain-intrinsic-size: auto 96px;
+}
+
+.sidebar-task-item {
+  content-visibility: auto;
+  contain-intrinsic-size: auto 52px;
 }
 
 .team-row-zebra-card:hover,